Computer Engineering Final Project: Temperature Regulated Fan

For my project, I decided to design a fan that responds to changes in temperature. When the temperature gets above a certain point, the fan will kick in to try to bring the temperature down. This is done through an Arduino Kit, a DC motor with a 3D printed fan, foam board, and lots of Duck Tape (lol).

Step one is to gather all the supplies.

(above are pictures of some of the electronic components needed)

*Make sure you have Arduino installed on a computer!!!

Supplies

DC Motor

Jumper wires (Tons!)

Arduino Uno R3 or RedBoard

Breadboard

330Ω Resistors

PN2222 Transistor

1N4001 diode

Temperature Sensor

LED

Paper and Pen

CAD software

Large foam poster board

Cutter Knife

Ruler

Lots of Duck Tape

Step 1: Setting Up the Motor

1. Connect Ground to the negative and 5V to the positive.

2. Place the transistor with the flat side facing right.

3. Connect a wire from the 1st socket right of the transistor to Ground(-).

4. Connect a wire from the 3rd socket of the transistor to "d11".

5. Connect a 330 resistor from the middle socket to the other side of the Breadboard.

6. Connect a wire from the other side of the resistor to "-9" on the RedBoard.

7. Connect the black end of the DC motor to the same row as the other side of the wire that connects to the 3rd socket of the transistor.

8. Connect the red end of the motor to a row above.

9. Connect a diode from the row you just placed the red end of the motor to the row you placed the black end. (Make sure the part of the diode with the thick black tip is facing north).

10. Connect a wire from the row with the think black end of the diode to Power(+).

Basically, set up the motor exactly the way it is presented in the above image.

Step 2: Hooking Up the Temperature Sensor

On another area, on the same half of the breadboard (not on the opposite side like in the picture), the DC motor was attached, place the temperature sensor in the same direction the transistor was placed.

Connect:

Top - Ground(-)

Middle - A0 on RedBoard

Bottom - Power(+)

Basically: Follow the picture again without placing the temperature sensor on the other half of the Breadboard.

Step 3: The LED

Place the LED with the shorter end facing you

Connect a 330 resistor from the negative end of the LED to Ground(-)

Connect a wire from the positive end of the LED to pin 13

Congratulations, you have completed the setup!!

Step 4: Code Time

HERE IS A PICTURE OF THE FINAL WIRING SET UP ON MY BREADBOARD AND REDBOARD!!

Now for the code! The comments explain what each part does

//Variables
const int temperaturePin = 0;<br>const int motorPin = 9;

void setup()
{
  pinMode(motorPin, OUTPUT);
  pinMode(13, OUTPUT);
  Serial.begin(9600);
}
float getVoltage(int pin)
{
  return (analogRead(pin) * 0.004882814);
}

void loop()
{

// this tells you what the voltage and temperature is so that it can be printed in the Serial Monitor
  float voltage, degreesC, degreesF;
  voltage = getVoltage(temperaturePin);
  degreesC = (voltage - 0.5) * 100.0;
  degreesF = degreesC * (9.0/5.0) + 32.0;

  
//Prints the Stuff
  Serial.print("voltage: ");
  Serial.print(voltage);
  Serial.print("  deg C: ");
  Serial.print(degreesC);
  Serial.print("  deg F: ");
  Serial.println(degreesF);
  
  //If the temp gets higher than 80 degrees, then, turn on the fan
  if (degreesF >= 80){
    digitalWrite(13, LOW);
    motorOnThenOffWithSpeed();
  }

//if it is lowe than 80 degrees then flash the LED.
  else{
    digitalWrite(13, LOW);   // Turn on the LED
    delay(100);              // Wait for one second
    digitalWrite(13, HIGH);    // Turn off the LED
    delay(100);
  }
 
}

//This method opporates the fan. 
void motorOnThenOffWithSpeed()
{

//Variables
  int Speed1 = 200;  // between 0 (stopped) and 255 (full speed)
  int Time1 = 12000;  // milliseconds for speed 1

  int Speed2 = 0;   // between 0 (stopped) and 255 (full speed)
  int Time2 = 3000;  // milliseconds to turn the motor off

  //Turns it on for 12 seeconds then turns it off
  analogWrite(motorPin, Speed1);  // turns the motor On
  delay(Time1);                   // delay for onTime milliseconds
  analogWrite(motorPin, Speed2);  // turns the motor Off
  delay(Time2);                   // delay for offTime milliseconds
}